The present invention relates to a device for holding a rotor on the spin arbor of a rotor spin test machine. The spin arbor is equipped with a first clamping element and a second clamping element with axial freedom which contact the face areas of the rotor. Centering surfaces are provided between the spin arbor and rotor for the co-axial alignment of the spin arbor and rotor when the rotor is not rotating.
Such devices serve the purpose of holding a rotor on the spin arbor of a rotor spin testing machine. For safety reasons, rotors that are exposed to high loads in service due to centrifugal forces must be subjected to test runs on spin test stands at speeds that are above the maximum service speed. In this manner, rotors of insufficient strength are detected and eliminated.
Rotors must be centered when they are clamped onto the spin arbor of the spin testing machine in order to avoid large vibration amplitudes during the overspeed test. To achieve centered clamping of a rotor having an axial bore hole, the spin arbor or a part connected with same, is equipped with a centering surface, for instance a collar, which locates the centering surface of the rotor, for instance the face area of the axial bore hole of the rotor. By means of these centering surfaces, the rotor can be centered during mounting. A rotor, thus centered, is positioned between a first clamping element which is preferably fixed to the spin arbor and a second clamping element with axial freedom, and is clamped securely in this centered position between the clamping elements by one or several screw connectors, for example.
Based on the design of the spin testing machine, a certain amount of eccentricity of the rotor is permissible, which generally can be safely accommodated even if the rotor centering is not very accurate. Because of the action of centrifugal forces upon the material of the rotor and the resulting expansion of the axial bore hole of the rotor, it is possible, that the centering of the rotor deteriorates to non-permissible values.